Driver Porting Layer (DPL) Interrupt Prioritization

Table of Contents

• Introduction
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

Introduction

This examples demonstrates the prioritization of interrupts in VIM through nesting of 3 Timer interrupts of different priority.

The example does the below

• Sets up Timer's 0,1,2 with same tick period.
• Sets up Timer interrupt with Timer 0 being highest priority, TImer 2 lowest.
• Nesting of interrupts is visualised with the help of trace buffer which captures the start and end of each Timer ISR.
• Timer2 is started first followed by Timer1 and then Timer0.
• Timer2 Interrupts gets nested by Timer1 interrupt which in turn gets nested by Timer0 interrupt.
• The trace macros used are -
  • 0xA0 - Timer0 ISR start
  • 0xB0 - Timer0 ISR end
  • 0xA1 - Timer1 ISR start
  • 0xB1 - Timer1 ISR end
  • 0xA2 - Timer2 ISR start
  • 0xB2 - Timer2 ISR end

Note

This example uses SysCfg to configure priority of Timer interrupts. For configuring the priority of interrupts which are not supported by SysCfg, use the element "HwiP_Params.priority" in HwiP. Priority can be specified from a level of 0 to 15, where 0 denotes highest priority.

Supported Combinations

Parameter	Value
CPU + OS	r5fss0-0 freertos
	r5fss0-0 nortos
Toolchain	ti-arm-clang
Board	am263x-cc, am263x-lp
Example folder	examples/kernel/dpl/interrupt_prioritization/

Steps to Run the Example

• When using CCS projects to build, import the CCS project for the required combination and build it using the CCS project menu (see Using SDK with CCS Projects).
• When using makefiles to build, note the required combination and build using make command (see Using SDK with Makefiles)
• Launch a CCS debug session and run the executable, see CCS Launch, Load and Run
• The trace gets printed and can be used to verify interrupt nesting and prioritization.

See Also

Driver Porting Layer (DPL)

Sample Output

Shown below is a sample output when the application is run,

[DPL] Interrupt prioritization Test Started...
[DPL] All timers stopped
[DPL] Printing Trace -
A2 - A1 - A0 - B0 - B1 - B2 - A2 - A1 - A0 - B0 - B1 - B2 - A2 - A1 - A0 - B0 - B1 - B2 - A2 - A1 - A0 - B0 - B1 - B2 -
[DPL] Interrupt prioritization Test Passed!
All tests have passed!!